Molecular Surveillance In Early Breast Cancer Using The Tumor-Informed ctDNA Assay Myriad Genetics Precise MRD Test; A Prospective Observational Multicenter Study (The MRD Molecular Surveillance Study)

Eligibility Criteria * Men or women who have a diagnosis of histological confirmed EBC (stage I, II or III) of any histopathology and any subtype (hormone-receptor positive or negative, HER2-positive, or negative). * Have tumor tissue available of sufficient quality for processing by Myriad Genetics. * Participant must be willing to provide serial blood samples at specific timepoints specific for each subgroup of interest per the Schedule of Activities * Age ≥18 years at enrollment * Arm A: Participants undergoing neoadjuvant systemic therapy: those with newly diagnosed untreated EBC of any subtype, stage I-II-II, who are scheduled to receive neoadjuvant systemic therapy of any type (i.e. chemotherapy, targeted therapy, immunotherapy, endocrine therapy) including a combination of agents, prior to undergoing breast surgery * Arm B: Participants with TNBC or HER2-positive EBC (T1a, T1b, N0): those with newly diagnosed and untreated TNBC or HER2-positive EBC who have a plan to undergo upfront breast surgery as part of their standard of care treatment * Arm C: Participants who receive an adjuvant CDK4/6-inhibitor (i.e., abemaciclib or ribociclib): those who have a diagnosis of hormone-receptor positive, HER2-negative, stage I-II-III EBC who have a plan to receive adjuvant abemaciclib or adjuvant ribociclib as part of their standard of care treatment * Arm D: Participants who receive an adjuvant PARP-inhibitor (i.e., olaparib): those who have a germline pathogenic mutation (i.e. …